Opponents of a planned high-rise near the foot of the Brooklyn Bridge in DUMBO sued to stop the project this week on the grounds that the city colluded with the developer and allowed him to expand the perimeter of his project site to take advantage of zoning perks.

The suit by the nascent DUMBO Neighborhood Foundation names the Department of City Planning, the City Planning Commission, the City Council, the Department of Education, and the School Construction Authority as guilty of improperly allowing the development company Two Trees Management to win a zoning change that paves the way for a planned 17-story project that includes a public middle school as a sweetener to seal the deal.

“There was a concerted effort to advance this project at any cost,” said Gus Sheha, a plaintiff in the case. “When you connect the dots, it’s apparent that people didn’t do their due diligence for a reason: they wanted to pass this.”

Coming just weeks after the release of documents revealing that the development’s promised middle school may have failed to meet city standards when the project was approved earlier this year, the suit alleges that the city officials “failed to fulfill their respective obligations to conduct a full, fair and objective examination of the appropriateness of including a middle school as part of the Dock Street Project as well as to conduct a full, fair and objective comparison of alternative middle school sites.”

“All evidence points towards a pattern of cooperation (if not collusion) between [the city] and Two Trees, which rendered selection of the Dock Street project as the site of a new school a foregone conclusion, and rendered any efforts to assess the potential impacts of such school (whether they were seriously undertaken or not), a fallacy,” continued the complaint, which also cited the city’s flipflop over the need for a new middle school in the neighborhood.

The group contends that Dock Street should not have qualified for as a “General Large Scale Development” — a jargony designation that gives developers of plots larger than 1-1/2 acres additional flexibility “in order to achieve a superior site plan.” But the key requirement is that all of the included plots are “designated as a tract, all of which is to be used, developed or enlarged as a unit.”

The suit claims that in order to reach the 1-1/2-acre threshold, Two Trees included properties that it doesn’t intend to raze — namely, a parcel across the street that currently houses the beloved Galapagos Art Space.

“The Galapagos Art Space is not contiguous and it’s not coming down, so it is not contributing to the new development,” said Sheha.

The suit goes on to contend that if the Galapagos plot — which is within 800 feet of the waterfront — is considered part of the Dock Street development, then the entire project should have been forced to comply with “waterfront block” regulations, which were not studied throughout the city’s land use review.

Barbara Wagner, a spokeswoman for Two Trees, claimed the suit was bunk.

“These allegations are without merit,” she said. “Two Trees complied with all of the legal and environmental requirements and properly obtained all necessary approvals from the city.”

For its part, the city Law Department declined to address the specifics of the case, which was made public on Wednesday.

“We have just received the legal papers and are reviewing them thoroughly,” said Deputy Chief Robin Binder.